"Koinobori"
-Carp streamers, windsoks or fish kites-

"Koinobori", carp-shaped streamers, or carp windsocks, decorate the landscape of Japan from April through early May, in honor of Children's Day (originally Boys' festival) on May 5. In Japanese culture, the carp symbolizes courage and strength because of its ability to swim up a waterfall.
Originally, the streamers were used by samurai warriors on the battlefield. Whenever the ancient warriors were on the battlefield, they wore full yoroi armor and flew streamers. The streamers were painted in various colors and shapes. Some of them had carp pictures on them. They became "carp streamers" at the beginning of the modern age. Since the carp's courage and strength is a trait desired in boys, families traditionally have flown koinobori from their homes to honor their sons.